• Title/Summary/Keyword: resistance inhibition

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Antibacterial effect of bee venom against Gram-positive and negative bacteria isolated from mastitis in dairy cattle (봉독의 젖소 유방염 유래 그람 양성 및 음성 세균별 항균효과 분석)

  • Jung, Sukhan;Oh, Sang-Ik;Lee, Han-Gyu;Jung, Young-Hun;Hur, Tai-Young;Han, Sangmi;Baek, Kui-Jeong;Cho, Ara
    • Korean Journal of Veterinary Service
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    • v.44 no.3
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    • pp.169-174
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    • 2021
  • Mastitis is an inflammatory condition of the mammary gland, most often caused by bacterial infections, resulting in significant economic losses to the dairy industry. Antimicrobial resistance has been of great concern because of the extensive clinical use of antibiotics. For this reason, the development of new compounds as an alternative treatment to bovine mastitis is needed. Bee venom has been widely used as an oriental treatment for several inflammatory diseases and bacterial infections. The aim of the present study was to evaluate the antimicrobial activity of bee venom on bacteria isolated from bovine mastitis. A total of 107 isolates from bovine mastitic milk samples collected in 2019 and 2020 in Jeonbuk province. All bacterial isolates were tested for susceptibility to bee venom of the honey bee (Apis mellifera). In order to obtain comprehensive antibacterial activities of the bee venom, we measured the minimal inhibitory concentration (MIC) of the bee venom against bacterial strains. Bee venom showed significant inhibition of bacterial growth of Gram-negative bacteria Citrobacter spp., Escherchia coli, Klebsiella spp., Pseudomonas spp., Serratia spp. and Raoultella with MIC values of 96, 81, 72, 230, and 85 ㎍/mL, respectively, and Gram-positive bacterial Enterococcus spp., Staphylococcus spp. and Streptococcus spp. with MIC values of 29, 21 and 16 ㎍/mL, respectively. The results indicated that the MIC values were different depending on the bacterial strains, and those of Gram-positive bacteria were lower than those of Gram-negative bacteria for bee venom. These findings suggested that bee venom could be an effective antimicrobial treatment for bovine mastitis; however, further research is necessary to evaluate the mechanism underlying the antimicrobial action, its effectiveness/safety in vivo and effective application for therapeutic use.

Characteristics of Cancer Stem Cells and Immune Checkpoint Inhibition (암줄기세포의 특성 및 면역관문억제)

  • Choi, Sang-Hun;Kim, Hyunggee
    • Journal of Life Science
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    • v.29 no.4
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    • pp.499-508
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    • 2019
  • Cancer stem cells (CSCs), which are primarily responsible for metastasis and recurrence, have self-renewal, differentiation, therapeutic resistance, and tumor formation abilities. Numerous studies have demonstrated the signaling pathways essential for the acquisition and maintenance of CSC characteristics, such as WNT/${\beta}$-catenin, Hedgehog, Notch, B lymphoma Mo-MLV insertion region 1 homolog (BMI1), Bone morphogenetic protein (BMP), and TGF-${\beta}$ signals. However, few therapeutic strategies have been developed that can selectively eliminate CSCs. Recently, neutralizing antibodies against Cytotoxic T-lymphocyte associated protein 4 (CTLA-4) and Programmed cell death protein 1 (PD-1)/Programmed death-ligand 1 (PD-L1), immune checkpoint inhibitors (ICIs), have shown promising outcomes in clinical trials of melanoma, lung cancer, and pancreatic cancer, as well as in hematologic malignancies. ICIs are considered to outperform conventional anticancer drugs by maintaining long-lasting anti-cancer effects, with less severe side effects. Several studies reported that ICIs successfully blocked CSC properties in head and neck squamous carcinomas, melanomas, and breast cancer. Together, these findings suggest that novel and effective anticancer therapeutic modalities using ICIs for selective elimination of CSCs may be developed in the near future. In this review, we highlight the origin and characteristics of CSCs, together with critical signaling pathways. We also describe progress in ICI-mediated anticancer treatment to date and present perspectives on the development of CSC-targeting ICIs.

α-Mangostin and Apigenin Induced Cell Cycle Arrest and Programmed Cell Death in SKOV-3 Ovarian Cancer Cells

  • Ittiudomrak, Teeranai;Puthong, Songchan;Roytrakul, Sittiruk;Chanchao, Chanpen
    • Toxicological Research
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    • v.35 no.2
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    • pp.167-179
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    • 2019
  • Ovarian cancer is the fifth main cause of pre-senescent death in women. Although chemotherapy is generally an efficient treatment, its side effects and the occurrence of chemotherapeutic resistance have prompted the need for alternative treatments. In this study, ${\alpha}$-mangostin and apigenin were evaluated as possible anticancer alternatives to the chemotherapeutic drug doxorubicin, used herein as a positive control. The ovarian adenocarcinoma cell line SKOV-3 (ATCC No. HTB77) was used as model ovarian cancer cells, whereas the skin fibroblast line CCD-986Sk (ATCC No. CRL-1947) and lung fibroblast line WI-38 (ATCC No. CCL-75) were used as model untransformed cells. Apigenin and doxorubicin inhibited the growth of SKOV-3 cells in a dose- and time-dependent manner. After 72 hr exposure, doxorubicin was mostly toxic to SKOV-3 cells, whereas apigenin was toxic to SKOV-3 cells but not CCD-986Sk and WI-38 cells. ${\alpha}$-Mangostin was more toxic to SKOV-3 cells than to CCD-986Sk cells. A lower cell density, cell shrinkage, and more unattached (floating round) cells were observed in all treated SKOV-3 cells, but the greatest effects were observed with ${\alpha}$-mangostin. With regard to programmed cell death, apigenin caused early apoptosis within 24 hr, whereas ${\alpha}$-mangostin and doxorubicin caused late apoptosis and necrosis after 72 hr of exposure. Caspase-3 activity was significantly increased in ${\alpha}$-mangostin-treated SKOV-3 cells after 12 hr of exposure, whereas only caspase-9 activity was significantly increased in apigenin-treated SKOV-3 cells at 24 hr. Both ${\alpha}$-mangostin and apigenin arrested the cell cycle at the $G_2/M$ phase, but after 24 and 48 hr, respectively. Significant upregulation of BCL2 (apoptosis-associated gene) and COX2 (inflammation-associated gene) transcripts was observed in apigenin- and ${\alpha}$-mangostin-treated SKOV-3 cells, respectively. ${\alpha}$-Mangostin and apigenin are therefore alternative options for SKOV-3 cell inhibition, with apigenin causing rapid early apoptosis related to the intrinsic apoptotic pathway, and ${\alpha}$-mangostin likely being involved with inflammation.

The Roles of Lactic Acid Bacteria for Control of Fungal Growth and Mycotoxins (곰팡이 생육 및 곰팡이 독소 생산의 억제에 있어서의 유산균의 역할)

  • Kim, Jihoo;Lee, Heeseob
    • Journal of Life Science
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    • v.30 no.12
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    • pp.1128-1139
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    • 2020
  • Over recent years, it has become evident that food and agricultural products are easily contaminated by fungi of Aspergillus, Fusarium, and Penicillium due to rapid climate change, which is not only a global food quality concern but also a serious health concern. Owing to consumers' interest in health, resistance to preservatives such as propionic acid and sorbic acid (which have been used in the past) is increasing, so it is necessary to develop a substitute from natural materials. In this review, the role of lactic acid bacteria as a biological method for controlling the growth and toxin production of fungi was examined. According to recent studies, lactic acid bacteria effectively inhibit the growth of fungi through various metabolites such as organic acids with low molecular weight, reuterin, proteinaceous compounds, hydroxy fatty acids, and phenol compounds. Lactic acid bacteria effectively reduced mycotoxin production by fungi via adsorption of mycotoxin with lactic acid bacteria cell surface components, degradation of fungal mycotoxin, and inhibition of mycotoxin production. Lactic acid bacteria could be regarded as a potential anti-fungal and anti-mycotoxigenic material in the prevention of fungal contamination of food and agricultural products because lactic acid bacteria produce various kinds of potent metabolic compounds with anti-fungal activities.

Growth Inhibitory and Pro-Apoptotic Effects of Hirsuteine in Chronic Myeloid Leukemia Cells through Targeting Sphingosine Kinase 1

  • Gao, Shan;Guo, Tingting;Luo, Shuyu;Zhang, Yan;Ren, Zehao;Lang, Xiaona;Hu, Gaoyong;Zuo, Duo;Jia, Wenqing;Kong, Dexin;Yu, Haiyang;Qiu, Yuling
    • Biomolecules & Therapeutics
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    • v.30 no.6
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    • pp.553-561
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    • 2022
  • Chronic myeloid leukemia (CML) is a slowly progressing hematopoietic cell disorder. Sphingosine kinase 1 (SPHK1) plays established roles in tumor initiation, progression, and chemotherapy resistance in a wide range of cancers, including leukemia. However, small-molecule inhibitors targeting SPHK1 in CML still need to be developed. This study revealed the role of SPHK1 in CML and investigated the potential anti-leukemic activity of hirsuteine (HST), an indole alkaloid obtained from the oriental plant Uncaria rhynchophylla, in CML cells. These results suggest that SPHK1 is highly expressed in CML cells and that overexpression of SPHK1 represents poor clinical outcomes in CML patients. HST exposure led to G2/M phase arrest, cellular apoptosis, and downregulation of Cyclin B1 and CDC2 and cleavage of Caspase 3 and PARP in CML cells. HST shifted sphingolipid rheostat from sphingosine 1-phosphate (S1P) towards the ceramide coupled with a marked inhibition of SPHK1. Mechanistically, HST significantly blocked SPHK1/S1P/S1PR1 and BCR-ABL/PI3K/Akt pathways. In addition, HST can be docked with residues of SPHK1 and shifts the SPHK1 melting curve, indicating the potential protein-ligand interactions between SPHK1 and HST in both CML cells. SPHK1 overexpression impaired apoptosis and proliferation of CML cells induced by HST alone. These results suggest that HST, which may serve as a novel and specific SPHK1 inhibitor, exerts anti-leukemic activity by inhibiting the SPHK1/S1P/S1PR1 and BCR-ABL/PI3K/Akt pathways in CML cells, thus conferring HST as a promising anti-leukemic drug for CML therapy in the future.

3-Deoxysappanchalcone Inhibits Cell Growth of Gefitinib-Resistant Lung Cancer Cells by Simultaneous Targeting of EGFR and MET Kinases

  • Jin-Young Lee;Seung-On Lee;Ah-Won Kwak;Seon-Bin Chae;Seung-Sik Cho;Goo Yoon;Ki-Taek Kim;Yung Hyun Choi;Mee-Hyun Lee;Sang Hoon Joo;Jin Woo Park;Jung-Hyun Shim
    • Biomolecules & Therapeutics
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    • v.31 no.4
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    • pp.446-455
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    • 2023
  • The mechanistic functions of 3-deoxysappanchalcone (3-DSC), a chalcone compound known to have many pharmacological effects on lung cancer, have not yet been elucidated. In this study, we identified the comprehensive anti-cancer mechanism of 3-DSC, which targets EGFR and MET kinase in drug-resistant lung cancer cells. 3-DSC directly targets both EGFR and MET, thereby inhibiting the growth of drug-resistant lung cancer cells. Mechanistically, 3-DSC induced cell cycle arrest by modulating cell cycle regulatory proteins, including cyclin B1, cdc2, and p27. In addition, concomitant EGFR downstream signaling proteins such as MET, AKT, and ERK were affected by 3-DSC and contributed to the inhibition of cancer cell growth. Furthermore, our results show that 3-DSC increased redox homeostasis disruption, ER stress, mitochondrial depolarization, and caspase activation in gefitinib-resistant lung cancer cells, thereby abrogating cancer cell growth. 3-DSC induced apoptotic cell death which is regulated by Mcl-1, Bax, Apaf-1, and PARP in gefitinib-resistant lung cancer cells. 3-DSC also initiated the activation of caspases, and the pan-caspase inhibitor, Z-VAD-FMK, abrogated 3-DSC induced-apoptosis in lung cancer cells. These data imply that 3-DSC mainly increased mitochondria-associated intrinsic apoptosis in lung cancer cells to reduce lung cancer cell growth. Overall, 3-DSC inhibited the growth of drug-resistant lung cancer cells by simultaneously targeting EGFR and MET, which exerted anti-cancer effects through cell cycle arrest, mitochondrial homeostasis collapse, and increased ROS generation, eventually triggering anti-cancer mechanisms. 3-DSC could potentially be used as an effective anti-cancer strategy to overcome EGFR and MET target drug-resistant lung cancer.

A Study on the Antifungal Properties of Ranunculaceae Herbal Medicines (미나리아재비과 한약재의 항진균성 검증 및 비교 연구)

  • Jae-yeoup Lim;Sang Ki Choi
    • Journal of Life Science
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    • v.34 no.6
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    • pp.393-398
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    • 2024
  • The purpose of this study was to verify the antifungal properties of various herbal medicines belonging to the Ranunculaceae family and to find an extraction method effective in inhibiting fungal growth. When antifungal activity was measured in a liquid medium with extracts obtained by either hot water extraction or organic solvent extraction of the herbal medicines Clematis apiifolia, Coptis chinensis, and Pusatilla chinensis, effective results were obtained from the chloroform extract. In addition, fungal growth inhibition experiments were performed on unicellular fungi, Candida albicans, Candida tropicalis, and Candida lusitaniae, and on filamentous fungi, such as Pythium ultimum, Aspergillus fumigatus, and Fusarium oxysporum, using disk diffusion experiments on solid media. It was confirmed that P. chinensis extract has excellent antifungal properties against Candida spp. and C. apiifolia extract against filamentous mold. Finally, GC-MS analysis was performed to explore the useful antifungal substances present in the extract. As a result of the study, thurbergenone from C. apiifolia and 16-hydroxycleroda-3, 13(14)-dien-15, 16-olide (16-HCDO) from C. chinensis were confirmed as antifungal candidates. In conclusion, it was confirmed that C. apiifolia, C. chinensis, and P. chinensis have antifungal activity against various fungi, and in GC-MS analysis, all herbal medicines were confirmed to have different antifungal candidates. These results indicate that the Ranunculaceae family has evolved in several directions for fungal resistance traits.

Evaluation of 1,1,2-trichloroethylene Removal Efficiency Using Composites of Nano-ZnO Photocatalyst and Various Organic Supports (다양한 유기계 지지체와 광촉매 Nano-ZnO 복합체를 활용한 1,1,2-trichloroethylene 제거 효율 평가)

  • Jang, Dae Gyu;Ahn, Hosang;Kim, Jeong Yeon;Ahn, Chang Hyuk;Lee, Saeromi;Kim, Jong Kyu;Joo, Jin Chul
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.11
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    • pp.771-780
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    • 2014
  • In this study, the various organic supports (i.e., silicone, acrylonitrile-butadiene-styrene, epoxy, and, butadiene rubber) with great sorption capacity of organic contaminants were chosen to develop nano-ZnO/organic composites (NZOCs) and to prevent the detachment of nano-ZnO particles. The water resistance of the developed NZOCs were evaluated, and the feasibility of the developed NZOCs were investigated by evaluating the removal efficiency of 1,1,2-trichloroethylene (TCE) in the aqueous phase. Based on the results from water-resistance experiments, long-term water treatment usage of all NZOCs was found to be feasible. According to the FE-SEM, EDX, and imaging analysis, nano-ZnO/butadiene rubber composite (NZBC) with various sizes and types of porosity and crack was measured to be coated with relatively homogeneously-distributed nano-ZnO particles whereas nano-ZnO/silicone composite (NZSC), nano-ZnO/ABS composite (NZAC), and nano-ZnO/epoxy composite (NZEC) with poorly-developed porosity and crack were measured to be coated with relatively heterogeneously-distributed nano-ZnO particles. The sorption capacity of NZBC was close to 60% relative to the initial concentration, and this result was mainly attributed to the amorphous structure of NZBC, hence the hydrophobic partitioning of TCE to the amorphous structure of NZBC intensively occurred. The removal efficiency of TCE in aqueous phase using NZBC was close to 99% relative to the initial concentration, and the removal efficiency of TCE was improved as the amount of NZBC increased. These results stemmed from the synergistic mechanisms with great sorption capability of butadiene rubber and superior photocatalytic activities of nano-ZnO. Finally, the removal efficiency of TCE in aqueous phase using NZBC was well represented by linear model ($R^2{\geq}0.936$), and the $K_{app}$ values of NZBC were from 2.64 to 3.85 times greater than those of $K_{photolysis}$, indicating that butadiene rubber was found to be the suitable organic supporting materials with enhanced sorption capacity and without inhibition of photocatalytic activities of nano-ZnO.

Introduction and Expression of PAP gene using Agrobacterium in Scrophularia buergeriana Miquel (Agrobacterium을 이용한 PAP 유전자의 현삼으로 도입 및 형질발현)

  • Yu, Chang-Yeon;Seong, Eun-Soo;Lim, Jung-Dae;Huang, Shan-Ai;Chae, Young-Am
    • Korean Journal of Medicinal Crop Science
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    • v.9 no.2
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    • pp.156-165
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    • 2001
  • Exogeneous application of pokeweed antiviral protein (PAP), a ribosomal-inacivating protein in the cell wall of Phytolacca americana (pokeweed) protects heterologous plants from viral and fungal infection. A cDNA clone of PAP introduced into Scrophularia buergeriana Miquel by thransformation with Agrobacterium tumefaciences. For plant transformation, explants were precultured on shoot induction medium without kanamycin for 2-5 day, and then they were cocultured with Agrobacterium for 10 minutes. The explants were placed on co culture medium in dark condition, $28^{\circ}C$ for 2days. After explants were washed in MS liquid medium, they were transferred into selection medium including kanamycin 50mg/L (MS salts+1mg/ l BAP+2mg/ l TDZ+0,2mg/ l NAA+MS vitamin+3% sucrose+0.8% agar, pH5.8). From PCR analysis, NPT II band was confirmed in transgenic plant genome and showed resistance against fungi in antifungal activity test. Micro assay to which protein extracted from transgenic line were added, revealed hyphae growth inhibition and no spore germination at high concentration. The characteristics of inhibited hyphae was represented transparent and thin. Expression of PAP in transgenic plants offers the possibility of developing resistance to viral and fungal infection.

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Mechanism of Growth Inhibition in Herbicide-Resistant Transgenic Rice Overexpressing Protoporphyrinogen Oxidase (Protox) Gene (Protoporphyrinogen Oxidase (Protox) 유전자 과다발현 제초제 저항성 형질전환 벼의 생육저해 기작)

  • Kuk, Yong-In;Shin, Ji-San;Yun, Young-Beom;Kwon, Oh-Do
    • Korean Journal of Weed Science
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    • v.30 no.2
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    • pp.122-134
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    • 2010
  • We investigated the levels of resistance and accumulation of terapyrroles, reactive oxygen species, lipid peroxidation, and antioxidative enzymes for reasons of growth reduction in herbicide-transgenic rice overexpressing Myxococcus xanthus, Arabidopsis thaliana, and human protoporphyrinogen oxidase (Protox) genes. The transgenic rice overexpressing M. xanthus (MX, MX1, PX), A. thaliana (AP31, AP36, AP37), and human (H45, H48, H49) Protox genes showed 43~65, 41~72 and 17~70-fold more resistance to oxyfluorfen, respectively, than the wild type. Among transgenic rice lines overexpressing Protox genes, several lines showed normal growth compared with the wild type, but several lines showed in reduction of plant height and shoot fresh weight under different light conditions. However, reduction of plant height of AP37 was much higher than other lines for the experimental period. On the other hand, the reduction of plant height and shoot fresh weight in the transgenic rice was higher in high light condition than in low light condition. Enhanced levels of Proto IX were observed in transgenic lines AP31, AP37, and H48 at 7 days after seeding (DAS) and transgenic lines PX, AP37, and H48 at 14 DAS relative to wild type. There were no differences in Mg-Proto IX of transgenic lines except for H41 and H48 and Mg-Proto IX monomethyl ester of transgenic lines except for MX, MX1, and PX. Although accumulation of tetrapyrrole intermediates was observed in transgenic lines, their tetrapyrrole accumulation levels were not enough to inhibit growth of transgenic rice. There were no differences in reactive oxygen species, MDA, ALA synthesizing capacity, and chlorophyll between transgenic lines and wild type indicating that accumulated tetrapyrrole intermediate were apparently not high enough to inhibit growth of transgenic rice. Therefore, the growth reduction in certain transgenic lines may not be caused by a single factor such as Proto IX, but by interaction of many other factors.